Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5593C2F7EF5 for ; Tue, 15 Sep 2026 12:48:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789476501; cv=none; b=YpQdetIjZtpIbP7gCLEja4E8mTQYnC5k73RtAlGCRVyOAGHorOCMKjLYKlXvYzbIyq84JewPLCuSyNRH8d4Jx0su5bfCN6/7blEOlEWHUmlpiZUvaaq2I1WGQx6zzC/b9PL5PrGR/gVlrvkcmAVT1BfVEfaKRfp746qvLA2+aCI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789476501; c=relaxed/simple; bh=3BOedPtGj4ElEXzzm96+6Pyo1VCdKv117UEBGZMCuRA=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=Il5VecrAnSg60LpPgMUEL2d+fUkPCwy22zq8Tz+L3CCvAt4AfN58m8vQVLEaSs4neB572fQFr4LZY2SLgTbx3o+Rig2/p8lzanmE9KKsl3ERtRJnrziTIitE7yRpTZP0XAx91P+onRxXVmzOclO3EHm66lxWNEdDePxeb1V9DyI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fl3FPdLO; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fl3FPdLO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE1DA1F000FF; Tue, 15 Sep 2026 12:48:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789476499; bh=P6nG0AwMLIw1VHygU3Hwxb7RFUOnws6dkQPjd0/NX+k=; h=From:To:Cc:Subject:Date; b=fl3FPdLO+BANmqSWmH+ylrt1K8CojMUXW2+xYOG+Qqz3V5ey09bgWyFETyNuUkaaI 0DY+W5tYCLOUyibhuR1lY5rLGVmTcjlY+uiqdUMjWSO1T6uAZgjsYit+DDkrg4RX0b N3i9t4kdiqfOEvBaRb8mQ+PsVV50S4+vg+yJSC74vOOjkVSIVXr3tz7ayKxXvayceM oXKv9jlSm9khDMbB0DsM+xhUcRSS508xUNj0I0bNuXgIL0HohTI6TUhMt9AwFqPa5/ minfyow82vfvIMS4Ru/d45eQ21drKp3aqT1O3hKroM557Xngbf5HhGQSEuiL/IqNGS GvxX13H8qXBWA== From: Namjae Jeon To: stable@vger.kernel.org Cc: gregkh@linuxfoundation.org, sashal@kernel.org, Namjae Jeon , Kanishka De Silva , Farhad Alemi Subject: [PATCH 5.15.y] ksmbd: prevent out-of-bounds reads in share config responses Date: Tue, 15 Sep 2026 21:48:03 +0900 Message-Id: <20260915124808.6052-1-linkinjeon@kernel.org> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit [ Upstream commit f25e93768fcc5d8287e50b1ec52a42e4c276df34 ] Validate IPC share configuration payload sizes before consuming variable-length fields. Bound veto list parsing and account for the separator byte when deriving the path length. Fixes: a677ebd8ca2f ("ksmbd: validate payload size in ipc response") Reported-by: Kanishka De Silva Reported-by: Farhad Alemi Signed-off-by: Namjae Jeon --- fs/ksmbd/mgmt/share_config.c | 38 ++++++++++++++++++++++++++---------- fs/ksmbd/transport_ipc.c | 24 +++++++++++++++++------ 2 files changed, 46 insertions(+), 16 deletions(-) diff --git a/fs/ksmbd/mgmt/share_config.c b/fs/ksmbd/mgmt/share_config.c index e0a6b758094f..5e9959361239 100644 --- a/fs/ksmbd/mgmt/share_config.c +++ b/fs/ksmbd/mgmt/share_config.c @@ -87,9 +87,9 @@ static struct ksmbd_share_config *__share_lookup(const char *name) static int parse_veto_list(struct ksmbd_share_config *share, char *veto_list, - int veto_list_sz) + size_t veto_list_sz) { - int sz = 0; + size_t sz; if (!veto_list_sz) return 0; @@ -97,7 +97,7 @@ static int parse_veto_list(struct ksmbd_share_config *share, while (veto_list_sz > 0) { struct ksmbd_veto_pattern *p; - sz = strlen(veto_list); + sz = strnlen(veto_list, veto_list_sz); if (!sz) break; @@ -105,7 +105,7 @@ static int parse_veto_list(struct ksmbd_share_config *share, if (!p) return -ENOMEM; - p->pattern = kstrdup(veto_list, GFP_KERNEL); + p->pattern = kstrndup(veto_list, sz, GFP_KERNEL); if (!p->pattern) { kfree(p); return -ENOMEM; @@ -113,6 +113,9 @@ static int parse_veto_list(struct ksmbd_share_config *share, list_add(&p->list, &share->veto_list); + if (sz == veto_list_sz) + break; + veto_list += sz + 1; veto_list_sz -= (sz + 1); } @@ -158,13 +161,27 @@ static struct ksmbd_share_config *share_config_request(struct unicode_map *um, share->name = kstrdup(name, GFP_KERNEL); if (!test_share_config_flag(share, KSMBD_SHARE_FLAG_PIPE)) { - int path_len = PATH_MAX; + size_t path_len; - if (resp->payload_sz) + if (resp->payload_sz <= resp->veto_list_sz) { + ret = -EINVAL; + } else { path_len = resp->payload_sz - resp->veto_list_sz; - - share->path = kstrndup(ksmbd_share_config_path(resp), path_len, - GFP_KERNEL); + if (resp->veto_list_sz) + path_len--; + + if (!path_len) { + ret = -EINVAL; + } else { + share->path = kstrndup( + ksmbd_share_config_path(resp), + path_len, GFP_KERNEL); + if (!share->path) + ret = -ENOMEM; + else + ret = 0; + } + } if (share->path) { share->path_sz = strlen(share->path); while (share->path_sz > 1 && @@ -177,7 +194,8 @@ static struct ksmbd_share_config *share_config_request(struct unicode_map *um, share->force_directory_mode = resp->force_directory_mode; share->force_uid = resp->force_uid; share->force_gid = resp->force_gid; - ret = parse_veto_list(share, + if (!ret) + ret = parse_veto_list(share, KSMBD_SHARE_CONFIG_VETO_LIST(resp), resp->veto_list_sz); if (!ret && share->path) { diff --git a/fs/ksmbd/transport_ipc.c b/fs/ksmbd/transport_ipc.c index 7e6003c6cd9b..9d7b21257bca 100644 --- a/fs/ksmbd/transport_ipc.c +++ b/fs/ksmbd/transport_ipc.c @@ -475,13 +475,25 @@ static int ipc_validate_msg(struct ipc_msg_table_entry *entry) } else if (entry->type == KSMBD_EVENT_SHARE_CONFIG_REQUEST) { struct ksmbd_share_config_response *resp = entry->response; - if (resp->payload_sz) { - if (resp->payload_sz < resp->veto_list_sz) - return -EINVAL; + if (entry->msg_sz < sizeof(struct ksmbd_share_config_response)) + return -EINVAL; + + if (strnlen(resp->share_name, sizeof(resp->share_name)) == + sizeof(resp->share_name)) + return -EINVAL; + + if (resp->veto_list_sz > resp->payload_sz) + return -EINVAL; + + if (resp->flags != KSMBD_SHARE_FLAG_INVALID && + !(resp->flags & KSMBD_SHARE_FLAG_PIPE) && + resp->payload_sz <= resp->veto_list_sz) + return -EINVAL; + + if (check_add_overflow(sizeof(struct ksmbd_share_config_response), + resp->payload_sz, &msg_sz)) + return -EINVAL; - msg_sz = sizeof(struct ksmbd_share_config_response) + - resp->payload_sz; - } } return entry->msg_sz != msg_sz ? -EINVAL : 0; -- 2.34.1